写了很多年的AS3，最近接触U3D感觉事件机制没AS3的爽。咬紧牙关一鼓作气 基于C# 的委托实现了一版。废话不多说上干货。

EventDispatcher代码如下：

using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;
/**
 * EventDispatcher 类是可调度事件的所有类的基类
 * @author 回眸笑苍生
**/
public abstract class EventDispatcher : MonoBehaviour
{
 //定义委托
 public delegate void EventDelegate(EventObject evt);
 
 protected Dictionary<String,List<EventDelegate>> captureListeners = null;

 protected Dictionary<String,List<EventDelegate>> bubbleListeners = null;

 protected EventDispatcher _parent;

 public void addEventListener(String types, EventDelegate listener, bool useCapture = false, int priority = 0, bool useWeakReference=false)
 {
  Dictionary<String,List<EventDelegate>> listeners = null;
 
  if (listener == null)
  {
   throw new ArgumentNullException("Parameter listener must be non-null.");
  }
  if (useCapture)
  {
   if (captureListeners == null) captureListeners = new Dictionary<string, List<EventDelegate>>();
   listeners = captureListeners;
  }
  else
  {
   if (bubbleListeners == null) bubbleListeners = new Dictionary<string, List<EventDelegate>>();
   listeners = bubbleListeners;
  }
  List<EventDelegate> vector = null;
  if (listeners.ContainsKey (types))
  {
   vector = listeners[types];
  }
  if (vector == null)
  {
   vector = new List<EventDelegate>();
   listeners.Add(types, vector);
  }
  if (vector.IndexOf(listener) < 0)
  {
   vector.Add(listener);
  }
 }

 public void removeEventListener(String types, EventDelegate listener, bool useCapture = false)
 {
  if (listener == null)
  {
   throw new ArgumentNullException("Parameter listener must be non-null.");
  }
  Dictionary<string, List<EventDelegate>> listeners = useCapture ? captureListeners : bubbleListeners;
  if (listeners != null)
  {
   List<EventDelegate> vector = listeners [types];
   if (vector != null)
   {
    int i = vector.IndexOf(listener);
    if (i >= 0)
    {
     int length = vector.Count;
     for(int j = i+1;j < length;j++,i++)
     {
      vector[i] = vector[j];
     }

     listeners.Remove(types);

     foreach (KeyValuePair<String, List<EventDelegate>> o in listeners)
     {
      if(o.Key == null)
      {
       if (listeners == captureListeners)
       {
        captureListeners = null;
       }
       else
       {
        bubbleListeners = null;
       }
      }
     }
    }
   }
  }

 }

 public bool hasEventListener(String types)
 {
  return (captureListeners != null && captureListeners.ContainsKey(types)) || (bubbleListeners != null && bubbleListeners.ContainsKey(types));
 }

 public bool willTrigger(String types)
 {
  for (EventDispatcher _object = this; _object != null; _object = _object._parent)
  {
   if ((_object.captureListeners != null && _object.captureListeners.ContainsKey(types)) ||( _object.bubbleListeners != null && _object.bubbleListeners.ContainsKey(types)))
    return true;
  }
  return false;
 }

 public bool dispatchEvent(EventObject evt)
 {
  if (evt == null)
  {
   throw new ArgumentNullException("Parameter EventObject must be non-null.");
  }
  EventObject event3D = evt;
  if (event3D != null)
  {
   event3D.setTarget = this;
  }
  List<EventDispatcher> branch = new List<EventDispatcher> ();
  int branchLength = 0;
  EventDispatcher _object;
  int i, j = 0;
  int length;
  List<EventDelegate> vector;
  List<EventDelegate> functions;
  for (_object = this; _object !=null; _object=_object._parent)
  {
   branch.Add(_object);
   branchLength++;
  }
  for (i = branchLength - 1; i > 0; i--)
  {
   _object = branch[i];
   if (event3D != null)
   {
    event3D.setCurrentTarget = _object;
    event3D.setEventPhase = EventPhase.CAPTURING_PHASE;
   }
   if (_object.captureListeners != null)
   {
    vector = _object.captureListeners[evt.types];
    if (vector != null)
    {
     length = vector.Count;
     functions = new List<EventDelegate>();
     for (j = 0; j < length; j++) functions[j] = vector[j];
     for (j = 0; j < length; j++) (functions[j] as EventDelegate)(evt);
    }
   }
  }
  if (event3D != null)
  {
   event3D.setEventPhase = EventPhase.AT_TARGET;
  }
  for (i = 0; i < branchLength; i++) {
   _object = branch[i];
   if (event3D != null) {
    event3D.setCurrentTarget = _object;
    if (i > 0) {
     event3D.setEventPhase = EventPhase.BUBBLING_PHASE;
    }
   }
   if (_object.bubbleListeners != null) {
    vector = _object.bubbleListeners[evt.types];
    if (vector != null) {
     length = vector.Count;
     functions =  new List<EventDelegate>();
     for (j = 0; j < length; j++) functions.Add(vector[j]);
     for (j = 0; j < length; j++) (functions[j] as EventDelegate)(evt);
    }
   }
   if (!event3D.bubbles) break;
  }
  return true;
 }

}

EventPhase代码如下：

using UnityEngine;
using System.Collections;
/**
 * EventPhase 类可为 Event 类的 eventPhase 属性提供值。
 * @author 回眸笑苍生
**/
public class EventPhase
{
 
 public const int CAPTURING_PHASE = 1;
 
 public const int AT_TARGET = 2;
 
 public const int BUBBLING_PHASE = 3;
}

EventObject代码如下：

using UnityEngine;
using System.Collections;
using System;
/**
 * EventObject 类作为创建 Event 对象的基类，当发生事件时，Event 对象将作为参数传递给事件侦听器。
 * @author 回眸笑苍生
**/
public class EventObject
{
 public const String ACTIVATE = "activate";
 public const String ADDED = "added";
 public const String ADDED_TO_STAGE = "addedToStage";
 public const String CANCEL = "cancel";
 public const String CHANGE = "change";
 public const String CLEAR = "clear";
 public const String CLOSE = "close";
 public const String CLOSING = "closing";
 public const String COMPLETE = "complete";
 public const String CONNECT = "connect";
 public const String OPEN = "open";

 private EventDispatcher _target;
 private int _eventPhase;
 private EventDispatcher _currentTarget;
 private bool _bubbles;
 private bool _cancelable;
 private String _types;

 public EventObject(String types, bool bubbles=false, bool cancelable=false)
 {
  this._types = types;
  this._bubbles= bubbles;
  this._cancelable = cancelable;
 }

 public EventDispatcher target
 {
  get { return _target; }
 }

 internal EventDispatcher setTarget
 {
  set { _target = value; }
 }

 public EventDispatcher currentTarget
 {
  get { return _currentTarget; }
 }

 internal EventDispatcher setCurrentTarget
 {
  set { _currentTarget = value; }
 }

 public int eventPhase
 {
  get { return _eventPhase; }
 }

 internal int setEventPhase
 {
  set { _eventPhase = value; }
 }

 public bool bubbles
 {
  get { return _bubbles; }
 }

 public String types
 {
  get { return _types; }
 }

 public bool cancelable
 {
  get { return _cancelable; }
 }
}

在使用过程中 大家可以把 U3D中新建Class 默认继承的基类 换成 EventDispatcher 这样一来就拥有了和AS3一样的 事件机制了。

有什么Bug 欢迎大家多多指教。